Python 基础
了解python基本语法 尝试写简单的python程序
1 count = 0 2 age_to_guess = 23 3 4 while count<3: 5 age_guessed = int(input("age:")) 6 if age_guessed == age_to_guess: 7 print("congratulations") 8 break 9 elif age_guessed > age_to_guess: 10 print("Too big") 11 else: 12 print("Too small") 13 count = count + 1 14 if count == 3: 15 confirm_input = input("Do you want to play more?") 16 if confirm_input != "n": 17 count = 0
1 age_to_guess = 23 2 age_guessed = int(input("age:")) 3 4 if age_guessed == age_to_guess : 5 print("Congratulations") 6 elif age_guessed > age_to_guess: 7 print("Too big") 8 else: 9 print("Too small")
1 import sys 2 3 ''' 4 print(sys.path) #打印环境变量 5 print(sys.argv) #相对路径 可在后面加参数 6 ''' 7 8 #操作系统模块 9 import os 10 11 cmd_result = os.system("dir") #执行命令 不保存结果 12 print(cmd_result) #输出0 为什么? os.system是直接在频幕上输出 没返回 13 14 cmd_result_internal_storage = os.popen("dir") #打开的是一个内存地址 15 print(cmd_result_internal_storage) 16 cmd_result_content = os.popen("dir").read() #读操作 17 print(cmd_result_content) 18 19 os.mkdir("new_dir") #创建目录 20 21 msg = "我爱北京天安门" 22 23 msg_bytes= msg.encode("utf-8") 24 25 print(msg_bytes) 26 27 msg_str = msg_bytes.decode("utf-8") 28 29 print(msg_str)
python list 用法(增删改查):
1 #author F 2 3 names = ["num1", "num2", "num3", "num4", "num3"] 4 5 print(names[0]) 6 print(names[2]) 7 print(names[1:3]) #左顾右盼 从左边到右边 不包括右边 8 print(names[2:]) 9 print(names[:-1]) 10 print(names[-3:-1]) #左边必须小于右边 左边是开始取值的地方 右边是结束取值的地方 11 12 #增 13 names.append("num10086") #在后面追加 14 print(names) 15 16 names.insert(2, "num_") 17 print(names) 18 19 names.insert(4, "_num") 20 print(names) 21 22 #改 23 names[2] = "change2" 24 print(names) 25 26 #删 27 names.remove("change2") 28 print(names) 29 del names[3] 30 print(names) 31 names.pop() #弹出 输入下标->删下标单位 默认->最后一个 32 print(names) 33 34 #查 35 print(names.index("num3")) 36 print(names[names.index("num3")]) 37 print(names.count("num3")) 38 names.reverse() #反转 39 print(names) 40 names.sort() #按照字母顺序排序 特殊符号>数字>大写>小写 ascii码 41 print(names) 42 names2 = [1, 2, 3, 4] 43 names.extend(names2) 44 print(names) 45 del names2 46 # print(names2) #未定义 47 48 49 #清空 50 names.clear() 51 print(names)
执行结果:
1 D:\python\python\python.exe D:/xampp/htdocs/python/day2/list_cut.py 2 num1 3 num3 4 ['num2', 'num3'] 5 ['num3', 'num4', 'num3'] 6 ['num1', 'num2', 'num3', 'num4'] 7 ['num3', 'num4'] 8 ['num1', 'num2', 'num3', 'num4', 'num3', 'num10086'] 9 ['num1', 'num2', 'num_', 'num3', 'num4', 'num3', 'num10086'] 10 ['num1', 'num2', 'num_', 'num3', '_num', 'num4', 'num3', 'num10086'] 11 ['num1', 'num2', 'change2', 'num3', '_num', 'num4', 'num3', 'num10086'] 12 ['num1', 'num2', 'num3', '_num', 'num4', 'num3', 'num10086'] 13 ['num1', 'num2', 'num3', 'num4', 'num3', 'num10086'] 14 ['num1', 'num2', 'num3', 'num4', 'num3'] 15 2 16 num3 17 2 18 ['num3', 'num4', 'num3', 'num2', 'num1'] 19 ['num1', 'num2', 'num3', 'num3', 'num4'] 20 ['num1', 'num2', 'num3', 'num3', 'num4', 1, 2, 3, 4] 21 [] 22 23 进程已结束,退出代码0
python list 用法(复制 循环):
1 #author F 2 import copy 3 4 5 #copy 列表浅复制 6 7 names = ["name1", "name2", "name3", ["alibaba", "blili"], "name4", "name5"] 8 names2 = names.copy() #浅copy:只copy第一层地址 原因:复制的第二层列表的指针地址 9 print(names) 10 print(names2) 11 12 names[1] = "name_change" 13 # print(names) 14 # print(names2) 15 16 names[3][1] = "BLILI" 17 print(names) 18 print(names2) 19 20 ''' 21 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 22 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 23 ['name1', 'name_change', 'name3', ['alibaba', 'BLILI'], 'name4', 'name5'] 24 ['name1', 'name2', 'name3', ['alibaba', 'BLILI'], 'name4', 'name5'] 25 ''' 26 27 # = 列表复制 28 names = ["name1", "name2", "name3", ["alibaba", "blili"], "name4", "name5"] 29 names2 = names 30 print(names) 31 print(names2) 32 33 names[1] = "name_change" 34 # print(names) 35 # print(names2) 36 37 names[3][1] = "BLILI" 38 print(names) 39 print(names2) 40 ''' 41 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 42 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 43 ['name1', 'name_change', 'name3', ['alibaba', 'BLILI'], 'name4', 'name5'] 44 ['name1', 'name_change', 'name3', ['alibaba', 'BLILI'], 'name4', 'name5'] 45 ''' 46 47 # 模块复制 48 names = ["name1", "name2", "name3", ["alibaba", "blili"], "name4", "name5"] 49 names2 = copy.deepcopy(names) #深copy : 会占用两份独立的内存空间 慎用 50 print(names) 51 print(names2) 52 53 names[1] = "name_change" 54 # print(names) 55 # print(names2) 56 57 names[3][1] = "BLILI" 58 print(names) 59 print(names2) 60 ''' 61 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 62 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 63 ['name1', 'name_change', 'name3', ['alibaba', 'BLILI'], 'name4', 'name5'] 64 ['name1', 'name2', 'name3', ['alibaba', 'blili'], 'name4', 'name5'] 65 ''' 66 67 #循环 68 for i in names: 69 print(i) 70 71 print(names[0:-1:1]) #['name1', 'name_change', 'name3', ['alibaba', 'BLILI'], 'name4'] 72 print(names[0::1]) #['name1', 'name_change', 'name3', ['alibaba', 'BLILI'], 'name4', 'name5']
元组 浅copy补充
1 person = ["name", ["saving", 123]] 2 #浅copy的三种实现方式 3 ''' 4 p1 = copy.copy(person) 5 p2 = person[:] 6 p3 = list(person) 7 ''' 8 p1 = person[:] 9 p2 = person[:] 10 11 p1[0] = 'ale1' 12 p2[0] = 'feng' 13 14 p1[1][1] = 50 15 16 print(p1) #联合账号的用法 17 18 #元组 19 names = ('231', ' 21314') 20 # 元组只有index和count方法
1 what_he_does = ' plays ' 2 his_instrument = 'guitar' 3 his_name = 'Robert Jhonson' 4 artist_intro = his_name + what_he_does + his_instrument 5 6 print(artist_intro) 7 print(type(what_he_does)) 8 9 10 num = 1 11 string = '1' 12 print(num+int(string)) 13 14 word = 'word' 15 words = word*3 16 print(words) 17 18 word = 'word' 19 num = 1 20 astr = word * (len(word) - num) 21 print(astr) 22 23 word = 'friends' 24 find_the_evil_in_your_friends = \ 25 word[0] + word[2:4] + word[-3:-1] 26 print(find_the_evil_in_your_friends) 27 28 tel = '135-8866-9555' 29 hide_tel = tel.replace(tel[:9], '*'*9) 30 print(hide_tel) 31 32 search = '234' 33 num_a = '135-8855-2345' 34 num_b = '123-2346-2346' 35 print(search + ' is at ' + str(num_a.find(search)) + ' to ' + str(num_a.find(search)+len(search)) + ' of num_a') 36 print(search + ' is at ' + str(num_b.find(search)) + ' to ' + str(num_b.find(search)+len(search)) + ' of num_b') 37 38 39 print('{} a word she can get what she {} for.'.format('With', 'came')) 40 print('{prepositon} a word she can get what she {verb} for.'.format(prepositon='With', verb='came')) 41 print('{0} a word she can get what she {1} for.'.format('With', 'came')) 42 43 # city = input("write down the name of city:") 44 # url = "http://api.baidu.com/wather?city={}".format(city) 45 # print(url) 46 47 48 def f_c(c): 49 f = c*9/5 + 32 50 return str(f) + '°F' 51 52 fahrenheit = f_c(35) 53 print(fahrenheit)
